fbi history
National Archives
A technician in the single fingerprint section of the FBI Identification Division examining the hand of a deceased person in an effort to secure fingerprints. fingerprints, revealing a distinct white fingerprint pattern. The Lab had performed a “forensic first” in using the silver nitrate method – the prints were matched to members of the Barker/Karpis gang, who were promptly arrested. The silver nitrate method was promising, but only in certain situations. The FBI’s print examiners continued to study other methods of developing latent prints; in 1954, they implemented the use of ninhydrin, a chemical used to detect the amines, or protein residues, left behind by fingerprints, on porous surfaces. In the late 1970s, they tested and began to use lasers to detect latent prints. More recent developments have included the use of cyanoacrylate (superglue fumes), fluorescent powders and dyes, and alternate light sources. A look through the FBI’s Processing Guide for Developing Latent Prints reveals how enormously
sophisticated the art of detecting, enhancing, and analyzing latent prints has become. The type of chemical, powder, and light or laser used to reveal a print depends on a number of variables, including the type and condition of the surface on which the prints are deposited, as well as the kind of residue left behind by the print. According to Deputy Assistant Director for the FBI Laboratory’s Forensic Analysis Branch Melissa Smrz, then Acting Assistant Director of the FBI’s Laboratory Division, the FBI’s expertise in latent print development is not limited to present-day criminal cases. It’s also useful in missing person cases or “in mass disasters, disasters where you’ve got remains that don’t have the outer layer of the skin, but they do have the lower level. We have techniques that enable us to enhance the friction ridges so you can roll a print.”
100 Years of Protecting America
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